Effects of raloxifene and continuous combined hormone therapy on haemostasis variables: a multicenter, randomized, double-blind study.

Author(s): Sgarabotto M, Baldini M, Dei Cas A, Manotti C, Luciana Barilli A, Rinaldi M, Benassi L, Bacchi Modena A

Affiliation(s): Department of Obstetrics, Gynecologic and Neonatology. Parma University-Italy, v. Gramsci 14, Parma, Italy. M.Sgarabotto@libero.it

Publication date & source: 2007, Thromb Res., 119(1):85-91. Epub 2006 Feb 24.

INTRODUCTION: Hormone replacement therapy is known to increase the risk of thromboembolic events. We compared the effects of HRT and raloxifene on some haemostasis variables. MATERIALS AND METHODS: In a multicenter, double-blind study, 54 healthy postmenopausal women were randomized to receive either continuous treatment with 2 mg 17beta-estradiol plus 1 mg norethisterone acetate (n=30) or 60 mg raloxifene (n=24) daily for 12 months. Blood samples were collected at baseline and at 3, 6 and 12 months to evaluate therapy effects on some haemostasis variables (factor VII, factor VIII, prothrombin fragments 1 and 2, protein C, protein C activity, protein S, thrombin-antithrombin complex, D-dimer, antithrombin, fibrinogen and plasminogen activator inhibitor). RESULTS: Both raloxifene and continuous combined hormone therapy modified the haemostasis variables toward a more prothrombotic profile. Factor VIII (p<0.01) and fibrinogen (p<0.05) plasma levels significantly increased at 6 months, prothrombin fragments 1 and 2 (p<0.05) significantly increased at 12 months, whereas protein C activity (p<0.001) and antithrombin (p<0.01) significantly decreased at 12 months in both groups. CONCLUSIONS: Our results demonstrate that raloxifene and continuous combined hormone therapy exhibit the same prothrombotic profile. Both treatments induced an increase in procoagulant parameters at 6 months and a decrease in anticoagulant parameters at 12 months.